17. Determine the maximum force exerted during different time intervals.a. Tap and drag across the data from 0 s to 10 s.b. Choose Statistics from the Analyze menu.c. Record the maximum force in Table 2, rounding to the nearest 0.1 N.d. Choose Statistics from the Analyze menu to turn off statistics.18. Repeat Step 17 for the remaining 10 second intervals: 20−30 s, 40−50 s, 60−70 s, and 80−90 s.19. Calculate the difference between each maximum value and the next and record these values in Table 2.20. Tap and drag to highlight 0−90 s on the graph. Choose Curve Fit from the Analyze menu. Select Linear as the Fit Equation and record the slope (round to the nearest 0.01) in Table 3. Select OK.DATA
Table 1−Continuous GripTime intervalMaximum force (N)∆ Maximum force (N)0–10 s20–30 s40–50 s60–70 s80–90 sTable 2−Repetitive GripTime intervalMaximum force (N)∆ Maximum force (N)0–10 s20–30 s40–50 s60–70 s80–90 sTable 3
SlopePart I–Continuous grippingPart II–Repetitive grippingData Analysis1. Examine your graph and the data in Table 1. What conclusion can you draw about the number of individual muscle fibers that are firing in the last 10 s compared with the first 10 s?2. Is the change in number of muscle fibers that contract occurring at a constant rate?3. Use your knowledge of fast, slow, and intermediate skeletal muscle fibers to hypothesize which fibers are contracting in the first, third, and final 10 s intervals.4. How might you explain the subject’s response to coaching? This should be evident in the last 10 s of data for Parts I and II of the exercise. Discuss the possible involvement of the central nervous system, in addition to the muscle fibers.5. Compare the slopes recorded in Table 3. Give a possible explanation for the difference, if any, in muscle fatigue rates seen in continuous versus repetitive gripping.